The Saiyan society make so little sense it hurts. There's no way that a society of warriors, every member of which gets several times stronger each time they come close to death, and with access to healing pods capable of healing even the most grievous of injuries in a matter of days, hasn't produced anyone capable of even rivaling Frieza's 1st form.
It literally doesn't make sense. At all.
Well, the two things to consider are that, 1) Saiyans are
kinda' stupid, from everything we've seen (though hybrids do alright), and probably didn't think it through if they ever even realized it was happening to begin with, and 2) There's not actually much showing the strength-on-near-death thing is particularly notable. Most of the Z saiyans have this thing were they didn't actually get close to death, they outright died, usually
repeatedly. And beyond that, most of the notable ones were, well, odd, iirc. Royal bloodlines and junk.
And beyond that, there actually was saiyans outside the Z warrior ones that could match frieza's first form. They just didn't get much screentime, from what I recall.
But yeah, it's entirely possible that the majority of them didn't realize the battlehax, weren't really capable of taking advantage of it, or just flat out didn't get much out of it. All possibilities.
Though @ EH, sure, the guy probably
could, but it could be he found selling the planets off to be more amusing. Some folks like a conquest victory, some folks like an economic one.